2-methylene steroids and preparation thereof



United States Patent 3,205,243 Z-METHYLENE STEROIDS AND PREPARATION THEREOF Moises Riano, East Greenbush, and Andrew John Manson, North Greenbush,N.Y., assignors to Sterling Drug Inc., New York, N.Y., a corporation of Delaware No Drawing. Filed Nov. 7, 1963, Ser. No. 322,015 Claims. (Cl. 260-397.4)

This invention relates to novel unsaturated steroids and in particular resides in the concept of steroids of the 4- androstene series substituted by methylene in the 2-position, e.g., 2-methylene-4-androstenl7,B-ol-3-one and esters thereof, including 17a-lower-alkyl and 17a-lower-alkynyl derivatives thereof. The invention is also concerned with methods for preparing these steroids, and intermediates in their preparation.

The compounds of the invention are of the formula R CH? 3 butyl, ethynyl, l-propynyl, 2-propynyl, l-butynyl, and the like.

In the above formula, R, when carboxylic acyl, can be derived from any carboxylic acid conventionally employed in the steroid art having from one to about ten carbon atoms and having a molecular weight less than about 200. Representative of the acyl radical R is loweralkanoyl, e.g., formyl, acetyl, propionyl, butyryl, isobutyryl, capr-oyl, heptanoyl, octanoyl, tn'methylacetyl, and the like; carboxy-lower-alkanoyl, e.g., succinyl (fi-carboxypropionyl); cycloalkyl-lower-alkanoyl wherein cycloalkyl has 5-6 ring members, e.g., fi-cyclopentylpropionyl, fi-cyclohexylpropionyl, and the like; mpnocarbocyclic aroyl, e.g., benzoyl, p-toluyl, p-nitrobenzoyl, 3,4,5-trimethoxybenzoyl, p-chlorobenzoyl, and the like; monocarbocyclic aryl-lower-alkanoyl or -alkenoyl radicals, such as phenylacetyl, fi-phenylphopionyl, cinnamoyl, and the like; and monocarbocyclic aryloxy-lower-alkanoyl radicals, such as p-chlorophenoxyacetyl, and the like. A preferred class of monocarbocyclic aryl includes phenyl and phenyl substituted by from one to three substituents selected from lower-alkyl of 1-4 carbon atoms, lower-alkoxy of 1-4 carbon atoms, nitro, and halogen, including fluorine, chlorine, bromine and iodine.

The compounds of the invention can be prepared by two general methods:

(1) By dehydration of the corresponding 2a-hydroxymethyl compounds.

A compound of the formula R CH3 ice wherein R and R have the same meanings given above and R is hydrogen or carboxylic acyl, is treated with a base. In the case where R" is hydrogen, the elements of water are eliminated, and in the case where R" is carboxylic acyl, the elements of a carboxylic acid R"OH are eliminated, to yield a compound of Formula I. Only mild alkaline conditions, for example, potassium bicarbonate in methanol, are needed to effect dehydration, and in fact dehydration can be carried out without causing hydrolysis of an ester group at the 17-position.

A modification of the foregoing procedure comprises heating a compound of Formula H Where R and R" are hydrogen with an acid anhydride or acid halide, preferably at a temperature between about 50 C. and C. in a high boiling tertiaryamine solvent, for example, pyridine or collidine. Dehydration takes place as well as esterification of the 17-hydroxy group to give a compound of Formula I where R is carboxylic acyl. Esterification of the 17-hydroxy group when R is other than hydrogen requires a higher temperature and longer heating than in the case where R is hydrogen.

The starting materials of Formula II are prepared by microbiological reduction of the corresponding Z-hydroxymethylene-4-androsten-17B-ol-3-one compounds as described in the copending application of Nielson et 211., Serial No. 322,029, filed November 7, 1963, now U.S. Patent 3,198,809.

(2) By deamination of a 2a-aminomethyl-17a-R-4- androsten-17/3-ol-3-one, wherein R is hydrogen, loweralkyl or lower-alkynl.

The Zea-aminomethyl group can be unsubstituted aminomethyl (H NCH or one or both hydrogen atoms of the amino group can be substituted by organic radicals. Since the amine moiety is removed in the deamination process, its exact nature is not critical and it can be derived from any amine which will participate in the Mannich reaction used to produce the 2a-aminomethyl intermediates. EX- emplary of preferred types of amine moieties are amino, 'lower-alkylamino, di-lower-alkylamino, piperidino, morpholino and pyroolidino.

Examples of deaminating agents are activated magnesium silicate and bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium methoxide, and the like.

Amine elimination can also be effected by steam distillation or pyrolysis of an acid-addition salt of the 2daminomethyl steriod. In some instances the deamination occurs in the same reaction medium in which the 20: aminomethyl steroid is formed.

The intermediate 2ot-aminomethyl- 17a-R-4-androsten- 17fi-ol-3-ones are prepared as follows:

(a) By a Mannich reaction employing a l7a-R-4-androsten-17fl-ol-3-one, formaldehyde and an amine. Frequently, the intermediate Zea-aminomethyl-17ozR-4-androsten-17B-ol-3-one is not isolated but undergoes deamination in the same reaction medium to produce a 2- methylene compound of Formula I.

(b) By reduction of a 2u-cyano steroid:

CH 3 OH? HzNCHg--- A 2a-cyano-17a-R-4-androsten-17,8-01-3-0ne is converted to its 3-ethylene glycol ketal, the double bond either remaining in the 4-position or shifting to the 5-position. The ketal is then reduced with lithium aluminum hydride and cleaved with acid to produce Zea-aminomethyl-17zx-R-4-androsten-17fl-ol-3-one.

The structures of the compounds of the invention were established by elementary analysis, and by ultraviolet, infrared and NMR spectral studies.

Endocrinological evaluation of the compounds of Formula I has shown that they possess anabolic properties, exhibiting nitrogen retention and myotrophic activity with relatively little androgenic activity. The compounds are active both upon subcutaneous and oral administration.

The following examples will further illustrate the invention without the latter being limited thereby.

Example 1 .-1 713-acetoay-2-methylene-4-andr0sten-3-0ne To a solution of 2.9 g. of 2a-acetoxymethyl-4-androsten- 17fi-ol-3-one 17-acetate in 400 ml. of 80% aqueous methanol, 6 g. of KHCO was added. The suspension was stirred on a steam bath until solution was complete (0.5 hr.). The clear reaction mixture was kept at room temperature (25 C.) for sixteen hours. The solution was then evaporated under reduced pressure to small volume and a colorless material precipitated out. Distilled water (500 ml.) was added and the precipitated material separated by filtration, washed with water and dried, giving 2.3 g., M.P. 172-180 C. A portion of this material (1.3 g.) was chromatographed over 150 g. of activated magnesium silicate. The column was developed with approximately 100-125 ml. portions of solvents of the following composition: ether (6 portions); ether-benzene (9:1) (21 portions); ether-benzene (17:3) (19 portions); ether-benzene (3:1) (9 portions); and ether-benzene (1:1) (7 portions). All fractions were analyzed by thin layer chromatography. Fractions eluted by ether-benzene (9:1) and ether-benzene (17:3) were combined and the solvent evaporated, leaving 0.70 g. of crystalline 17 3- acetoxy-2-methylene-4-androsten-3-one. Recrystallization from methanol afforded pure material in the form of colorless rods, M.P. 194-196 C. (corn), [a] +132.l5 (0.51% in chloroform); ultraviolet maximum at 259-260 m (e=14,200); infrared absorption at 3.41, 3.51, 5.76, 6.00, 6.17, 6.88, 6.95 and 8.00 1.- The NMR spectrum was also in accord with the assigned structure.

Example 2.-17,B- (fl-cyclohexylpropionoxy) -2-methylene- 4 -andr0sten-3 -0ne 2u-hydroxymethyl-4-androsten-l7fi-ol-3-one (7.24 g.) was dissolved in 100 ml. of pyridine, previously dried over potassium hydroxide. fi-cyclohexylpropionic anhydride (15 ml.) was then added and the mixture was stirred for four hours at 60 C., for four hours at 80 C., and allowed to stand at room temperature overnight.

(1) LiAlH4 The reaction mixture was concentrated to a syrup, diluted with ether, washed with dilute sodium bicarbonate solution, dried over anhydrous sodium sulfate and concentrated to dryness. The residue was dissolved in cyclohexane and chromatographed on a column of 700 g. of silica gel. The column was eluted with pentane and with pentane containing gradually increasing amounts of ether. Pentane-ether 4:1 brought out one product which was recrystallized from ether and from ethyl acetate to give 176 ((3 cyclohexylpropionoxy)-2-methylene-4- androsten-B-one in the form of colorless plates, M.P. 150.0-

151.2 C. (corn), [u] =-|12l.9 (1% in chloroform); ultraviolet maximum at 260 m (e: 14,600); infrared absorption at 3.42, 3.50, 5.75, 6.01, 6.20, and 8.55 4.

Further elution of the chromatograph column with pentane-ether 1:1 brought out another product, unesterified at C-17, which was recrystallized from ether to give 2-methylene-4-androsten-17fl-ol-3-one, M.P. 136-142 C. (uncorr.); infrared absorption at 3.00, 3.40, 3.50, 5.74, 5.99, 6.16 and 6.21

Example 3 .-1 (fl-phenylpropionoxy -2-methy lene- 4 -andr0sten-3-0ne 17,6-capryloxy-Z-methylene-4-androsten-3 -one,

175-henzoyl0xy-2-methylene-4-androsten-3-one,

17 ,B- p-toluyloxy) -2-methylene-4-androsten-3 -one,

175- (p-nitrobenzoyloxy) -2-metl1y1ene-4-androsten-3-one,

17 {3- 3,4,5 -trimethoxybenzoyloxy) -2-methylene-4- androsten-3-one,

17 B- B-cyclopentylpropionoxy) -2-methylene-4- androsten-3-one,

17fl-phenylacetoxy-2-methylene-4-androsten-3 -one,

17B-cinnamoyloxy-Z-methylene-4-androsten-3-one, or

175- (p-chlorophenoxyacetoxy) -2-methylene-4-androsten- 3-one.

Example 4 2-methylene-l7ot-methyl 4 androstcn-l7/3-ol-3-one was prepared by treating 2ot-acetoxymethyl-l7tx-methyl-4- androsten-17B-ol-3-one with potassium bicarbonate in methanol according to the procedure described above in Example 1. There was thus obtained 2-methylene-17amethyl-4-androsten-17/3-ol-3-one, M.P. 189-193 C. (uncorr.), [a] =+l41.4 (0.58% in chloroform); ultraviolet maximum at 260 m (e=l4,000); infrared absorption at 2.93, 6.05 and 6.20 1. The NMR spectrum was in accord with the assigned structure.

Example 5.-2-methyIene-17ot-ethynyl-4-andr0sten- 1 7B-0l-3-0ne l7a-ethynyl-4-androsten-17,8-0l-3-one (24.0 g.) was suspended in 500 ml. of glacial acetic acid in a nitrogen atmosphere. Formaldehyde (12.0 ml. 40%) was added, the mixture heated to C. and then 12.0 g. of dimethylamine hydrochloride added. The reaction mixture was heated for three hours at boiling temperature, left overnight at room temperature and poured into ice-water. The mixture was filtered to remove unreacted starting material, and the filtrate was made alkaline with potassium bicarbonate and extracted with methylene dichloride. The extracts were dried over anhydrous sodium sulfate and concentrated, and the residue was dissolved in 500 ml. of methylene dichloride, stirred eighteen hours with 100 g. of activated magnesium silicate andpoured onto a column of 400 g. of activated magnesium silicate. The column was eluted with methylene dichloride. and with methylene dichloride-ether 1:1. The material brought out by the latter eluant was rechromatographed on 300 g. of activatedmagnesium silicate and eluted with benzene and benzene containing increasing amounts of ether. Benzene-ether 9:1 brought out the desired product which was recrystallized several times from acetone-hexane. to give Z-methylene 17a ethyny1-4-androsten-17 3 ol-3- one, M.P. 180.6-181.8 C. (corn), [a] =-}73.5 (1% in chloroform); ultraviolet maximum at 260 mu (e=13,900); infrared maxima at 2.90, 3.06, 3.41, 4.75, 5.28, 6.00, 6.15 'and 6.95 The nuclear magnetic resonance spectrum confirmed the presenceof the groupings =CH ECH and angular CH The same results can be obtained by replacing the dimethylamine hydrochloride in the foregoing preparation by a molar equivalent amount of dibutylamine hydrochloride, ethylamine hydrochloride, piperidine hydrochloride, pyrrolidine hydrochloride, morpholine hydrochloride, or 4-methylpiperidine hydrochloride.

Example 6 2-methylene-17a-ethynyl-4-androsten-17B-ol-3-one was prepared by treating Za-acetoXymethyl-l7a-ethynyl-4-androsten-17B-ol-3-one with potassium carbonate according to the procedure described above in Example 1. The product was identical with that obtained in Example 5.

Example 7 (a) Zen cyano 3 ethylenedioxy-4-androsten-J7B- 0l.-2u-cyano-4-androsten-17fl-ol-3-one (1.00 g.) was dissolved in 125 ml. of benzene and the solution refluxed under a water trap for 30 minutes to remove traces of water. Freshly distilled ethylene glycol (10 ml.) and 0.05 g. of sulfosalicylic acid were added, and the mixture was refluxed under a water trap for two and onehalf hours. Water (100 ml.) was added to the reaction mixture, and the benzene layer was separated, washed with 5% sodium bicarbonate solution and saturated sodium chloride solution, dried over anhydrous sodium sulfate and concentrated. The residue was crystallized from ethyl acetate to give 2a-cyano-3-ethylenedioxy-4-androsten-17,B-ol, M.P. 235239.2 C. (corn),

(1% in chloroform).

(b) 2a (aminomethyl) 4-andr0sten-17/3-0l-3-0ne.- A solution of 4.80 g. of 2a-cyano-3-ethylenedioxy-4-androsten-17/i-ol in 50 ml. of tetrahydrofuran was added dropwise to a suspension of lithium aluminum hydride in 500 ml. of ether in a nitrogen atmosphere. The reaction mixture was stirred for three hours, and then 6 ml. of water in 12 ml. of tetrahydrofuran was added dropwise and the mixture stirred for thirty minutes longer. The mixture was filtered and concentrated to dryness. The residue was dissolved in methylene dichloride and excess ethereal hydrogen chloride was added. The product which separated was collected, recrystallized from methanol-ether and from methanol-ethyl acetate and dried for twelve hours at 85 C. in vacuo to give 2m-(aminomethyl)-4-androsten-17,8-01-3-one in the form of its hydrochloride salt, M.P. 283.229l.2 C. (corn),

(1% in 95% ethanol); ultraviolet maximum at 242 mu (e=13,400); infrared absorption at 2.94, 3.42, 5.99, 6.19, 6.25, 6.33, 6.56 and 678-696;.

2a-(aminomethyl)-4-androsten-17B-ol-3-one can be converted to 2-methylene-4-androsten-17fi-ol-3-one by treating it with a deaminating agent such as activated mag- 6 nesium silicate or sodium methoxide, or by pyrolytic methods.

We claim:

1. The process for preparing a 2-methylene steroid which comprises heating under alkaline conditions a compound of the formula R CH3(\ Z OR, RO 011 wherein R is a member of the group consisting of hydrogen, lower-alkyl and lower-alkynyl; and R and R are members of the group consisting of hydrogen and carboxylic acyl having from one to ten carbon atoms and a molecular weight less than about 200.

2. The process for preparing a 2-methylene steroid which comprises heating with a member of the group consisting of an acid anhydride and an acid halide in a high boiling tertiary-amine solvent at a temperature between about 50 C. and C. a compound of the formula R CH3 HOCHr" wheren R is a member of the group consisting of hydrogen, lower-alkyl and lower-alkynyl.

3. The process for preparing a compound of the for mula to a Mannich reaction with an amine and formaldehyde and treating the resulting 2u-aminomethyl-l7u-R-4'androsten-l7 8-ol-3-one with a member of the group consisting of activated magnesium silicate, alkali metal hydroxides, alkali metal carbonates, and alkali metal lower-alkoxides; wherein R is a member of the group consisting of hydrogen, lower-alkyl and lower-alkynyl.

7 8 4. The process for preparing a compound of the forwhich comprises treating a 2a-aminomethy1-17a-R-4-anmllla drosten-17fl-ol-3-one, wherein R is a member of the group CH3 consisting of hydrogen, lower-alkyl and lower-alkynyl, CH3 3 with a member of the group consisting of activated mag- I 5 nesium silicate, alkali metal hydroxides, alkali metal carbonates, and alkali metal lower-alkoxides.

CH References Cited by the Examiner P UNITED STATES PATENTS 7 3,033,854 5/62 Eschenmoser 260-2395 which comprises heating an acid-addition salt of a 2w- 3:092,621 6/63 De Stevens 260-2395 aminomethyl-17a-R-4-androsten-17 6-01-3-one, wherein R 3,152,153 10/64 Evans et 260397-4 is a member of the group consisting of hydrogen, loweralkyl and loWer-alkynyl. OTHER REFERENCES The process for preparing a compound of the Dorfrnan et al., Steroids, vol. 1, pp. 185-209, p. 196 mula relied on, February 1963.

Edwards et al., Journal Med. Chem, vol. 6, pp. 178 182, March 1963.

R CH3 1 0H LEWIS GOTTS, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,205,243 September 7, 1965 Moises Riano et a1.

ppears in the above numbered pat- It is hereby certified that error a id Letters Patent should read as ent requiring correction and that the sa corrected below.

Column 6, lines 45 to 54, the upper right-hand portion of the formula should appear as shown below instead of as in the patent:

the lower left-hand portion of the column 7, lines 3 to 12,

shown below instead of as in the formula should appear as patent:

i CH3 Signed and sealed this 11th day of October 1966c [SEAL] Attest:

ERNEST W. SWIDER EDWARD J, BRENNER Attesting Officer Commissioner of Patents 

1. THE PROCESS FOR PREPARING A 2-METHYLENE STEROID WHICH COMPRISES HEATING UNDER ALKALINE CONDITIONS A COMPOUND OF THE FORMULA 